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ELECTRICAL SAFETY
Gerald P. Robinson Jr., P.E.
– Hatch Mott MacDonald
Electrical Safety in the Municipal Water and
Wastewater Environment
 Electrical Safety Statistics
– Annually about 8000 electrical injuries are sent to hospitals.
– Over 2000 workers are sent to burn centers from electrical
related injuries
– One person is killed by electrocution in the U.S. each day.
– Approximately 2/3 of the workers killed by electrocution
were not electrical workers.
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Electrical Safety in the Municipal Water and
Wastewater Environment
• Results of a Safety Survey conducted by NFPA
– Survey of 1200 electricians:
• 97% had experienced an electrical shock
• 26 had witnessed an electrical injury
• 58% were exposed to the possibility of an electrical
injury every day
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Electrical Safety in the Municipal Water and
Wastewater Environment
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• Electrical Safety in the United States Based on Three
Principals
– All Electrical Equipment and Conductors shall be
Listed/Labeled and Acceptable for Safe Electrical Operation
– All Electrical Equipment and Conductors shall be installed in
accordance with Nationally Accepted Codes and Standards
– All Electrical Equipment and Conductors shall be Operated &
Maintained in accordance with Nationally Accepted Safety
Standards
Electrical Safety in the Municipal Water and
Wastewater Environment
• Listed/Labeled and Acceptable Equipment
– National Electrical Code (NEC) requires equipment and
conductors to be “Acceptable to the authority having
jurisdiction (AHJ)”
• Listed / Labeled by an Nationally Recognized Testing
Laboratory (NRTL)
• Evaluated by the AHJ and determined to be “Acceptable”
– OSHA – 29CFR 1910.303 and 29CFR 1910.399
• Electrical equipment is acceptable only if it is listed, labeled,
or certified as safe by a NRTL
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Electrical Safety in the Municipal Water and
Wastewater Environment
• Effects of Sandy on NRTL Listed &
Labeled Electrical Equipment
– Did the NRTL listing remain in force after the
electrical equipment was submerged in
saltwater? (Listing Agency is UL for this equipment)
• “…the answer to the above questions is that
the Listing on the equipment can no longer
be considered valid, since the equipment
was subjected to a condition of being
submerged in water with other
contaminants or exposed to significant
damp conditions that were not within the
equipment or component listing. “
(UL Field Evaluation of a piece of submerged
electrical equipment from Sandy)
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Electrical Safety in the Municipal Water and
Wastewater Environment
• Installed in accordance with Nationally Accepted
Codes and Standards (sample of a few codes)
– National Fire Protection Association
• NFPA 70 – The National Electrical Code
• NFPA 820 – Standards for Fire Protection in Wastewater
Treatment and Collection Facilities
– Great Lakes Upper Mississippi Board of State Public Health
and Environmental Managers
• Recommended Standards for Wastewater Facilities
• Recommended Standards for Water Works
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Electrical Safety in the Municipal Water and
Wastewater Environment
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• Operated & Maintained in accordance with Nationally
Accepted Safety Standards
– OSHA - General Duty Clause states that an employer must
protect its employees from recognized hazards.
– NFPA 70E – Standard for Electrical Safety in the Workplace
Electrical Safety in the Municipal Water and
Wastewater Environment
• NFPA 70E – Standard for Electrical Safety in the
Workplace
– In 1976 OSHA and NFPA began working together to
address electrical safety in the workplace
– In 1979 the first edition of NFPA 70E “Standard for
Electrical Safety Requirements for Employee Workplaces”
was published
– NFPA 70E has become the “STANDARD” for Electrical
Safety in the Workplace and is used by OSHA to evaluate
electrical safety in the workplace using the General Care
Standard
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Electrical Safety in the Municipal Water and
Wastewater Environment
 Responsibilities
– The “Employer” is responsible for:
• Electrical Safety Program
– Up to date drawings and diagrams
– Arc Flash Analysis (updated every 5 years)
– Lockout / Tagout
• Safety Policies and Procedures
• Safety Training and Retraining
• Personal Protective Equipment(PPE)
– The “Employee” is responsible for:
• Following procedures established by the “Employer”
• Wearing Employer Provided PPE
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Electrical Safety in the Municipal Water and
Wastewater Environment
• Basic Electrical Hazards in the
Workplace
– Shock Hazard: A dangerous condition
associated with the possible release of
energy caused by contact or approach
to energized electrical conductors or
circuit parts.
– Arc Flash Hazard: A dangerous
condition associated with the possible
release of energy caused by an
electrical arc.
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Electrical Safety in the Municipal Water and
Wastewater Environment

OSHA & NFPA 70E Each have
Requirements for Working on
‘Live’ Equipment
–
Qualified electrical workers shall
not be asked to work on
equipment that is “hot” or “live”
except for two demonstrable
reasons:
•
De-energizing introduces
•
Infeasible due to equipment
design or operational
limitations (e.g.* voltage testing
additional or increased hazards
(e.g.* cutting ventilation to a
hazardous location* emergency
alarm systems or)
for diagnostics * start up testing)
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Electrical Safety in the Municipal Water and
Wastewater Environment
• Operations
– Circuit Breakers in Panelboards or Motor Control Centers
with the covers closed rated 600V and below (Cat 0 PPE)
– Motor Starters in Motor Control Centers and Individual
Enclosures with the covers closed rated 7.2kV and below
(Cat 0 PPE)
– Opening hinged covers to expose energized electrical
conductors or parts on equipment rated 240V or below
(Cat 0 PPE)
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Electrical Safety in the Municipal Water and
Wastewater Environment
• Cat 0 PPE
– (Natural Fiber Clothing)
•
•
•
•
•
Long Sleeve Natural Fiber Shirt
Natural Fiber Long Pants
Safety Glasses
Hearing Protection
Leather Gloves
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Electrical Safety in the Municipal Water and
Wastewater Environment
• Operations
– Energized Work on parts and conductors in equipment
operating between 240V - 600V (Cat 2 PPE)
– Circuit Breaker Operation on metal clad switchgear with
the door closed rated 1kV through 38kV (Cat 2 PPE)
– Work on 120V Control Circuits in metal clad switchgear
rated 1kV through 38kV (Cat 2 PPE)
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Electrical Safety in the Municipal Water and
Wastewater Environment
• Cat 2 PPE
– (Min Arc Rating of 8 cal/cm2)
•
•
•
•
•
•
•
•
Arc Rated long sleeve shirt
Arc Rated pants or coveralls
Arc Rated Face Shield
Hard Hat
Safety Glasses
Hearing Protection
Leather Gloves
Leather Work Shoes
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Electrical Safety in the Municipal Water and
Wastewater Environment
• Operations
– Removal of Bolted Covers on energized MCCs operating
at 600V and below (Cat 4 PPE)
– Insertion or Removal of a Energized MCC Bucket on
MCCs operating at 600V and below (Cat 4 PPE)
– Work on Control Circuits Greater than 120V in metal clad
switchgear rated 1kV through 38kV (Cat 4 PPE)
– Circuit Breaker Operation with door open on metal clad
switchgear rated 1kV through 38kV (Cat 4 PPE)
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Electrical Safety in the Municipal Water and
Wastewater Environment
• PPE
– Category 4 (Min Arc Rating of 40 cal/cm2)
• Arc Rated Coveralls or Flash Suit
• Arc Rated Flash Suite Hood
• FR Hardhat Liner
• Hard Hat
• Safety Glasses
• Hearing Protection
• Arc Rated Gloves
• Leather Work Shoes
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Electrical Safety in the Municipal Water and
Wastewater Environment
• Traditional Duplex Pump
Control Panel
– Inner Door only designed to
provide Voltage Protection – No
Arc Flash Protection
– Outer Door to be opened by
Qualified Persons Only
– Typical PPE Required
(arc flash analysis required)
• Cat 0 to open outer door
• Cat 2 to open inner door
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Electrical Safety in the Municipal Water and
Wastewater Environment
Effective Electrical Safety Program
Needs to Include:
• Management Commitment to
De-Energize all Electrical
Equipment for Service
• Up to Date Electrical Drawing
• Arc Flash Analysis
• Employee Training
• Personal Protective Equipment
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Electrical Safety in the Municipal Water and
Wastewater Environment
Questions ?
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